When transmitting a sequence of related images, it is useful to minimize the amount of information being transmitted using compression and/or other techniques in order to minimize bandwidth requirements and any undesired delay in rendering the images on a remote display. One such technique is color quantization. This technique employs a color map to reduce the amount of information being transmitted for each pixel. For example, instead of transmitting a “true color” 24-bit value for each pixel, an 8-bit color map index value is transmitted. In such case, a three to one reduction in transmitted bits is accomplished albeit at the expense of having far fewer colors available in the palette.
In many applications, such reduction in available colors is an acceptable trade-off for an increased image transfer rate. However, in other applications, it may result in objectionably diminished image quality. A fixed color map in such cases particularly aggravates the problem.